It looks like you're asking about "Nirvana" and also about "where did you sleep last night." I'll address both parts for you:

Nirvana

Nirvana is a concept primarily from Indian religions such as Buddhism, Hinduism, and Jainism. It refers to the ultimate spiritual goal - a state of liberation, enlightenment, and freedom from suffering and the cycle of rebirth (samsara). In Buddhism, achieving Nirvana means extinguishing desire, attachment, and ignorance, leading to profound peace and liberation. Additionally, "Nirvana" is also the name of a famous American rock band from the 1990s, known for hits like "Smells Like Teen Spirit."

Where Did You Sleep Last Night?

If you're asking me personally, as an AI, I don't sleep or have a physical presence. But if you want to know about the phrase "Where Did You Sleep Last Night," it is also the title of a traditional American folk song, famously covered by Nirvana during their MTV Unplugged performance. If you meant something else or want more details, feel free to clarify!